The Traíra (Hoplias sp.) or Lobo is a carnivorous freshwater fish of the family Characidae. The Traíra is one of Brazil’s most popular fish, found in nearly all regions of the country, in freshwater of lakes, ponds and rivers. In areas that provide good nutrition is common reaching 70 cm long, and some specimens exceed 2 kg in weight. One should be careful when handling it, because they tend to give very painful bites and they bleed profusely. It is undesirable for fish because it feeds voraciously on fish fry and young of other species. Traíras are sometimes confused with Piranhas by non-fishermen. It marked preference for the shadows and darkness. It is a territorial, cannibalistic fish, protect their offspring until they spread among marginal vegetation. Due to the characteristics of carnivores and their preference for the shadows and darkness.